/*
 * Copyright 1999-2101 Alibaba Group.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.alibaba.fastjson.serializer;

/**
 * circular references detect
 * 
 * @author wenshao<szujobs@hotmail.com>
 * 
 */
public final class JSONSerializerContext {
	public static final int DEFAULT_TABLE_SIZE = 128;

	private final Entry[] buckets;
	private final int indexMask;

	public JSONSerializerContext() {
		this(DEFAULT_TABLE_SIZE);
	}

	public JSONSerializerContext(int tableSize) {
		this.indexMask = tableSize - 1;
		this.buckets = new Entry[tableSize];
	}

	public final boolean put(Object o) {
		final int hash = System.identityHashCode(o);
		final int bucket = hash & indexMask;

		for (Entry entry = buckets[bucket]; entry != null; entry = entry.next) {
			if (o == entry.object) {
				return true;
			}
		}

		Entry entry = new Entry(o, hash, buckets[bucket]);
		buckets[bucket] = entry;

		return false;
	}

	protected static final class Entry {
		public final int hashCode;
		public final Object object;

		public Entry next;

		public Entry(Object object, int hash, Entry next) {
			this.object = object;
			this.next = next;
			this.hashCode = hash;
		}

	}
}
